Managing Shared Assembly Line Priority and Queue Allocation
Managing shared line priorities requires balancing station work content variance and commercial order margins to prevent bottleneck starvation.
Tactic Time Variance
Meaning
Deviation between the planned cycle time and the actual duration of a production task identifies inefficiencies in manual or automated assembly. Monitoring the difference between the planned duration of a task and the actual time taken reveals the stability of a production process. A positive tactic time variance indicates that a task took longer than the target, suggesting a potential problem with materials, tools, components or training.
Tracking this figure allows for the identification of trends before they impact the final delivery schedule.
Measurement Basis
Target time is usually established through work measurement studies or historical averages. Sensors on the equipment or manual logs recorded by operators provide the actual start and stop times. Comparing these two values for every cycle generates a data set for statistical analysis.
Root Analysis
Patterns in the data often point to specific causes like machine wear or inconsistent raw material quality. If the duration increases only during certain shifts, the variance may be related to staffing or environmental factors. Deepening the investigation involves correlating the time spikes with other process variables like temperature or batch number.
Process Correction
Results from this analysis lead to updates in standard work instructions or equipment settings. If the variance is consistently negative, meaning tasks are finished early, the target time might be adjusted to increase the planned throughput. Maintaining a low variance ensures that the entire assembly line remains synchronized, which prevents the buildup of inventory and reduces the stress on manual operators at the end of the line.